The handling of the key witness in the Damilola Taylor murder trial has raised questions about the place of rewards in criminal investigations.

Offering a reward for information in a criminal case is always a risky business. Does it encourage those too scared to speak out to come forward or lead someone to give false evidence?

The Damilola Taylor trial threw the spotlight on the issue after the key prosecution witness, a teenage girl, was effectively dismissed because her evidence was tainted by talk of a £50,000 reward put up by the Daily Mail.

Just give me the £50,000. Gimme, gimme, gimme, gimme, gimme.

Teenage witness Bromley

The 14-year-old, known only as "Bromley", presented dramatic evidence to the Old Bailey of how she had witnessed the attack on Damilola.

But days later her testimony was in tatters.

Not only had she stormed out of court after clashing with defence counsel, the judge, Mr Justice Hooper concluded that no jury could trust what she had said.

On one police tape, Bromley laughed about the reward offered by the newspaper. She sang "I'm in the money" and mimicked the hit television quiz show Who Wants to be a Millionaire?

In another interview, Bromley said to a guardian: "D'ya know, I figured how much I am going to give you."
"How much of what?" asked the guardian.

When this was put to her in court, she said that it had all been a joke and she wouldn't take the money even if it was offered to her.

But it did not end there. Bromley and her mother ran up a £4,000 hotel bill at the police's expense. Later, Sergeant Carolyn Crooks revealed to the Old Bailey that she had bought clothes and two mobile phones for the girl - but denied that they were inducements in return for evidence.

Eventually, Mr Justice Hooper said the evidence was "unreliable" because there was a very real danger Bromley had been persuaded to say what the police needed to hear.

Fraught with danger

Rodney Warren, chairman of the Criminal Law Solicitors Association, believes the practice of rewarding key witnesses for their evidence is fraught with danger.

It's the perception that's the danger - it would be there even if the witness was telling the truth

Rodney Warren

"Rewards have always been thought to be a helpful way of persuading a reluctant witness that it would be worthwhile coming forward," he told BBC News Online.

It's the perception that's the danger - it would be there even if the witness was telling the truth Rodney Warren, Criminal Law Solicitors Association "But the danger is increasing that the witness may be motivated to receive the money."

Mr Warren said the existence of a reward could put the truthfulness of a witness's evidence in doubt.

He believes the practice should be regulated in the same way as controls on newspapers offering witnesses money for their stories.

That separate practice of offering payments to witnesses for interviews after a trial could become a criminal offence under proposals recently announced by government.

Guidelines needed

Mr Warren said: "I think there would have to be the clearest possible guidelines in the way in which rewards were offered, decisions made about them and the way they are structured.

They [witness payments] remain, over all, bad news for justice

Roger Bingham

"If it concerns a principal witness, the perception is the witness may not be a witness of truth.

"It's the perception that's the danger. It would be there even if the witness was telling the truth."

Roger Bingham, of civil rights group Liberty, said in an ideal world witness rewards would not be used at all.

Bu he said if they are used, everyone must be made aware of it and the effect it could have on a court case.
"It has to be entirely open in court," he told BBC News Online.